#include <stdio.h>
#include <string.h>

int main()
{
    int n,i;
    char ch1[60]="abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz";
    char ch2[60],*p;

    scanf("%d",&n);
    getchar();
    scanf("%s",ch2);

    for(i=0;i<strlen(ch2);i++)
    {
        ch2[i]=ch1[(ch2[i]-97)+(n%26)];
    }

    puts(ch2);
    return 0;
}